ANCHORAGE, Alaska — Greenhouse gas emissions remain the primary threat to the preservation of polar bear populations worldwide. This conclusion holds true under both a reduced greenhouse gas emission scenario that stabilizes climate warming and another scenario where emissions and warming continue at the current pace, according to updated U.S. Geological Survey research models. (more…)
Tag Archives: U.S. Geological Survey
Efforts continue to increase population of endangered bird
NECEDAH, Wis. – Four whooping crane chicks raised in captivity began their integration into the wild Saturday as part of the continuing effort to increase the wild population of this endangered species. (more…)
Southwestern Bird and Reptile Distributions to Shift as Climate Changes
Dramatic distribution losses and a few major distribution gains are forecasted for southwestern bird and reptile species as the climate changes, according to just-published research by scientists with the U.S. Geological Survey, the University of New Mexico, and Northern Arizona University.
Overall, the study forecasted species distribution losses – that is, where species are able to live – of nearly half for all but one of the 5 reptile species they examined, including for the iconic chuckwalla. The threatened Sonoran (Morafka’s) desert tortoise, however, is projected to experience little to no habitat losses from climate change. (more…)
ANCHORAGE — Nearly 25 years after the Exxon Valdez oil spill injured wildlife off the coast of Alaska, a new report issued today by the U.S. Geological Survey indicates that sea otters have returned to pre-spill numbers within the most heavily oiled areas of Prince William Sound.
Sea otters in the path of the oil incurred heavy mortality when 42 million liters of Prudhoe Bay crude oil were spilled in Prince William Sound in March 1989, with an estimated loss of several thousand otters. Through long-term data collection and analysis, scientists found that sea otters were slow to recover, likely because of chronic exposure to lingering oil. Other studies documented persistence of oil in the sea otter’s intertidal feeding habitats. (more…)
Computer model can help with current, future clean-up efforts
St. Petersburg, Fla. – A newly developed computer model holds the promise of helping scientists track and predict where oil will go after a spill, sometimes years later. U.S. Geological Survey scientists developed the model as a way of tracking the movement of sand and oil found along the Gulf of Mexico since the Deepwater Horizon oil spill. The new tool can help guide clean-up efforts, and be used to aid the response to future oil spills. (more…)
PASADENA, Calif. — Earthquake activity in the New Madrid Seismic Zone in the central United States does not seem to be slowing down. In a new study published in the journal “Science,” seismologists Morgan Page and Susan Hough of the U.S. Geological Survey investigate whether current quakes in the region could be aftershocks of large earthquakes that occurred 200 years earlier.
Using extensive computer modeling of aftershock behavior, they show that the dearth of moderate (Magnitude 6) earthquakes following the series of large earthquakes in 1811-1812, combined with the high rates of small earthquakes today, is not consistent with the long-lived aftershock hypothesis. (more…)
THREE RIVERS, Calif, — Trees do not slow in their growth rate as they get older and larger — instead, their growth keeps accelerating, according to a study published in the journal Nature.
“This finding contradicts the usual assumption that tree growth eventually declines as trees get older and bigger,” says Nate Stephenson, the study’s lead author and a forest ecologist with the U.S. Geological Survey. “It also means that big, old trees are better at absorbing carbon from the atmosphere than has been commonly assumed.” (more…)
ANN ARBOR — Declines of the food resources that feed lake organisms are likely causing dramatic changes in the Great Lakes, according to a new study.
The study, led by the U.S. Geological Survey and co-authored by three University of Michigan researchers, found that since 1998, water clarity has been increasing in most Great Lakes, while phytoplankton (the microscopic water organisms that feed all other animals), native invertebrates and prey fish have been declining. These food web changes fundamentally affect the ecosystem’s valuable resources and are likely caused by decreasing levels of lake nutrients, and by growing numbers of invasive species such as zebra and quagga mussels. (more…)